Cover empty sets in for_each

[pselle]

We should check earlier for empty lists -- having it after set-specific checking meant we were missing empty lists/empty sets, and users would get an error they shouldn't get.

Fixes #22281

[aarcro]

Will this apply to for_each in dynamic? I'm trying to do:

resource "aws_api_gateway_usage_plan" "these" {                                                               
  for_each = var.apig_plans                                                                                   
                                                                                                              
  name = "${local.namespace}-${each.key}-plan"                                                                
                                                                                                              
  api_stages {                                                                                                
    api_id = aws_api_gateway_rest_api.rest_api[0].id                                                          
    stage  = aws_api_gateway_rest_api.rest_api[0].name                                                        
  }                                                                                                           
                                                                                                              
  dynamic "quota_settings" {                                                                                  
    for_each = [for v in [each.value["quota"]] : v if v != {}]                                                
                                                                                                              
    content {                                                                                                 
      limit  = quota_settings.value["limit"]                                                                  
      offset = quota_settings.value["offset"]                                                                 
      period = quota_settings.value["period"]                                                                 
    }                                                                                                         
  }                                                                                                           
                                                                                                              
  dynamic "throttle_settings" {                                                                               
    for_each = [for v in [each.value["throttle"]] : v if v != {}]                                             
                                                                                                              
    content {                                                                                                 
      burst_limit = throttle_settings.value["burst_limit"]                                                    
      rate_limit  = throttle_settings.value["rate_limit"]                                                     
    }                                                                                                         
  }                                                                                                           
}                                                                                                             

But the empty list in for_each, still tries to execute content with an empty object:

  on .terraform/modules/zappa/zappa/api-keys.tf line 15, in resource "aws_api_gateway_usage_plan" "these":
  15:       limit  = quota_settings.value["limit"]
    |----------------
    | quota_settings.value is object with no attributes

The given key does not identify an element in this collection value.

[pselle]

@aarcro No, this is unrelated to dynamic's for_each. This would be a separate bug to file, if you could do that!

[galindro]

@apparentlymart When this change is planned to be released?

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

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